Lec 2 Flashcards
What is the basic unit of radiation measurement defined as the number of disintegrations per second for a gram of pure radium?
Curie
1 Curie equals approximately 3.7 x 10^10 disintegrations/sec.
What is the term for atoms with the same atomic number but different mass numbers?
Isotopes
Examples include Iodine-131 and Iodine-127.
What is the definition of a nuclide?
A specific type of atom with specific atomic number (Z) and mass number (A) in a specific nuclear state.
What is the term for atoms with the same mass number but different atomic numbers?
Isobars
Examples include 36S and 36Ar.
What type of radiation has the highest ionizing ability and cannot pass through paper?
Alpha rays
Alpha particles consist of 2 protons and 2 neutrons.
What is the energy of alpha particles?
5 MeV
What type of radiation is represented by electrons or positrons and can penetrate just the skin surface?
Beta rays
Beta decay involves the transformation of neutrons into protons.
What is the energy range for beta particles?
KeV to MeV
What type of radiation has no charge, no mass, and the least ionization?
Gamma rays
Gamma rays are photons with very short wavelengths.
What is the definition of half-life?
The time required for one-half of a given quantity of a substance to undergo change.
What is the half-life of Technetium-99m (Tc-99m)?
6 hours
What is the term for the process where a heavy nucleus breaks into fragments, releasing energy?
Fission reaction
What happens during beta decay?
A neutron is converted into a proton and an electron (beta particle) is emitted.
In nuclear equations, what must be identical on both sides of the reaction arrow?
The total mass and the sum of atomic numbers
What is the absorbed dose of radiation measured in?
Rad or Gray (Gy)
1 Gray equals 0.01 joules absorbed by 1 kg of biological tissue.
What is the unit used to measure the effect of ionizing radiation in biological tissue?
Rem or Sievert (Sv)
What type of decay involves the emission of gamma ray photons from an excited nucleus?
Isomeric Transition
What are the basic atomic particulates?
- Electron
- Neutrino
- Mesons
- Protons
- Neutrons
What is the term for atoms with the same number of neutrons but different atomic numbers?
Isotones
Example includes 131I and 132Xe.
What happens during electron capture?
A proton captures an electron, converting to a neutron and emitting a neutrino.
What is the range of half-lives for radioactive isotopes?
From a fraction of a second to a billion years
